Attachment 128047 Details for Bug 98759 – Loop on EINTR

[patch] Loop on EINTR

0001-backlight-Protect-iface-writes-against-signal-interr.patch (text/plain), 1.93 KB, created by Chris Wilson on 2016-11-17 19:23:34 UTC

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Creator: Chris Wilson

Created: 2016-11-17 19:23:34 UTC

Size: 1.93 KB

patch

obsolete

>From e3db32aadaccdea2d0af0d340fc605b514512578 Mon Sep 17 00:00:00 2001
>From: Chris Wilson <chris@chris-wilson.co.uk>
>Date: Thu, 17 Nov 2016 19:22:02 +0000
>Subject: [PATCH] backlight: Protect iface writes against signal interruptions
>
>Handle EINTR (and EAGAIN) by repeating until the write is complete.
>
>References: https://bugs.freedesktop.org/show_bug.cgi?id=98759
>Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
>---
> src/backlight.c | 28 ++++++++++++++++++++++------
> 1 file changed, 22 insertions(+), 6 deletions(-)
>
>diff --git a/src/backlight.c b/src/backlight.c
>index d020a7c..3cba577 100644
>--- a/src/backlight.c
>+++ b/src/backlight.c
>@@ -48,6 +48,7 @@
> #include <fcntl.h>
> #include <unistd.h>
> #include <dirent.h>
>+#include <errno.h>
> 
> #include <xorg-server.h>
> #include <xf86.h>
>@@ -216,6 +217,24 @@ __backlight_read(const char *iface, const char *file)
> }
> 
> static int
>+writen(int fd, const char *value, int len)
>+{
>+	int ret;
>+
>+	do {
>+		ret = write(fd, value, len);
>+		if (ret < 0) {
>+			if (errno == EAGAIN || errno == EINTR)
>+				continue;
>+
>+			return ret;
>+		}
>+	} while (value += ret, len -= ret);
>+
>+	return 0;
>+}
>+
>+static int
> __backlight_write(const char *iface, const char *file, const char *value)
> {
> 	int fd, ret;
>@@ -224,7 +243,7 @@ __backlight_write(const char *iface, const char *file, const char *value)
> 	if (fd < 0)
> 		return -1;
> 
>-	ret = write(fd, value, strlen(value)+1);
>+	ret = writen(fd, value, strlen(value)+1);
> 	close(fd);
> 
> 	return ret;
>@@ -458,7 +477,7 @@ err:
> int backlight_set(struct backlight *b, int level)
> {
> 	char val[BACKLIGHT_VALUE_LEN];
>-	int len, ret = 0;
>+	int len;
> 
> 	if (b->iface == NULL)
> 		return 0;
>@@ -467,10 +486,7 @@ int backlight_set(struct backlight *b, int level)
> 		level = b->max;
> 
> 	len = snprintf(val, BACKLIGHT_VALUE_LEN, "%d\n", level);
>-	if (write(b->fd, val, len) != len)
>-		ret = -1;
>-
>-	return ret;
>+	return writen(b->fd, val, len);
> }
> 
> int backlight_get(struct backlight *b)
>-- 
>2.7.4
>

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Attachments on bug 98759: 128037 | 128038 | 128047 | 128048 | 128049

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